The massive overlap of content types and modules when it comes to Social Networking

It suddenly dawned on my that most of my site is massively redundant and unwieldy, especially when looked at through the lens of what a social networking site is all about. I was thinking in an outdated paradigm, and many of the borders that I - and likely other people - think within when creating websites are pretty- much illusory. I'm now thinking there has got to be a way to massively simplify and improve this whole concept. Let me explain:

• I currently have the site laid out into section. Blogs, Forums, Reviews, Gallery, etc. All of these sections are then sub-divided by category and/or user
• I currently have Taxonomy, Buddylist, and Organic Groups organizing content/people, under the illusion that they need to perform separate functions

What I've realized is that when it comes down to it, a site such as mine really only involves three things: People, Content, and Categories

• People create Content and Categories
• People are organized by Category
• Content is organized by Person or Category
• The concept of content type (blog, forum, review, poll, gallery, etc.) is only another type of category

So I'm thinking what needs to be done is to consolidate a LOT of functionality, which will in turn deeply decrease the learning curve and improve usability of the site.

Category structure needs to be consolidated/integrated somehow.

• All content types under one vocabulary, with the possible exception of separate content types/vocabulary for Admin use only.
• Taxonomy needs to be set up for freetagging, so users can create categories without admin intervention. Is freetagging compatible with a hierarchical taxonomy? (i.e. Hobbies > Pets > Dogs > Spaniels but also the ability to have multiple parent categories and create new categories on-the-fly?)
• Tags need to be somehow associated with Organic Groups, so someone could create a group for i.e. Pets, have a customizable page, etc., and automatically see all content categorized under pets or its sub-categories
• Buddylist seems redundant, if each user automatically gets an OG i.e. in the taxonomy Networking > People > Username and has control over who joins. But how to achieve the automatic group creation, and tight integration like Buddylist?

I suppose what I'm saying is, is this all possible with existing modules? The main catches I can see are:

• I don't know how to have each user automatically associated with their own group in a particular category
• The whole idea of Taxonomy, while incredibly useful, is quite aggravating. The distinction between Vocabularies and Terms poses completely unnecessary barriers. User access and content type should be limited by term rather than vocabulary for a more flexible system.
• How to arrange tight integration between groups and taxonomy terms? How does one reconcile the idea of anyone being able to create a group or term, while still maintaining a hierarchical structure so sub-terms are visible on a group page? What about limiting members of a group, but not limiting access to a taxonomy term? This is a catch where I'm afraid I have no ideas so far.

Well, I'm running out of steam and losing coherence. What's more, you're probably getting sick of seeing bullet points. :) I'll probably post more or amend later. I'm really looking forward to everyone's thoughts on this though!